[ARM] pxa: add ability to set suspend mode

PXA processors have several low-power modes. Currently kernel supports
only one of these modes for PM_SUSPEND_MEM.

This patch adds ability to set desired suspend mode for PXA27x based
machines.

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Reviewed-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Eric Miao <eric.miao@marvell.com>

arch/arm/mach-pxa/include/mach/pxa27x.h

@@ -16,4 +16,7 @@
 #define ARB_DMA_PARK		(1<<25)	   /* Be parked with DMA when idle */
 #define ARB_CORE_PARK		(1<<24)	   /* Be parked with core when idle */
 #define ARB_LOCK_FLAG		(1<<23)	   /* Only Locking masters gain access to the bus */
+
+extern int __init pxa27x_set_pwrmode(unsigned int mode);
+
 #endif /* __MACH_PXA27x_H */

arch/arm/mach-pxa/pxa27x.c

@@ -203,6 +203,23 @@ static struct clk_lookup pxa27x_clkregs[] = {
 #define SAVE(x)		sleep_save[SLEEP_SAVE_##x] = x
 #define RESTORE(x)	x = sleep_save[SLEEP_SAVE_##x]
 
+/*
+ * allow platforms to override default PWRMODE setting used for PM_SUSPEND_MEM
+ */
+static unsigned int pwrmode = PWRMODE_SLEEP;
+
+int __init pxa27x_set_pwrmode(unsigned int mode)
+{
+	switch (mode) {
+	case PWRMODE_SLEEP:
+	case PWRMODE_DEEPSLEEP:
+		pwrmode = mode;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
 /*
  * List of global PXA peripheral registers to preserve.
  * More ones like CP and general purpose register values are preserved
@@ -254,7 +271,7 @@ void pxa27x_cpu_pm_enter(suspend_state_t state)
 		pxa_cpu_standby();
 		break;
 	case PM_SUSPEND_MEM:
-		pxa27x_cpu_suspend(PWRMODE_SLEEP);
+		pxa27x_cpu_suspend(pwrmode);
 		break;
 	}
 }